Revenue Contract Balances (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Revenue from Contract with Customer [Abstract]
Contract assets	$ 1,295.0	$ 1,755.5
Contract with Customer, Asset, Net, Current, Increase (Decrease)	$ (460.5)
Contract with Customer, Asset, Net, Current, Increase (Decrease), Percent	(26.20%)
Contract liabilities	$ 4,085.1	3,314.2
Contract with Customer Liability, Current, Increase (Decrease)	$ 770.9
Contract with Customer Liability, Current, Increase (Decrease), Percent	23.30%
Contract assets (liabilities), Current, Net	$ (2,790.1)	$ (1,558.7)
Contract assets (liabilities), Current, Net, Increase (Decrease)	$ (1,231.4)
Costs in Excess of Billings (Billings in Excess of Cost), Current, Net, Increase (Decrease), Percent	(79.00%)
Contract with Customer, Asset, Increase (Decrease) for Contract Acquired in Business Combination	$ 5.7
Deferred Revenue, Revenue Recognized	2,814.6
Contract with Customer, Performance Obligation Satisfied in Previous Period	$ 21.8